MCPat
MCPat is a meta-circular pattern matching library. The patterns are compiled to lisp using patterns, which maks the compiler extensible through patterns. In addition, pattern search and selection is controlled through an extensible CLOS-based mechanism, so that programs can describe the most efficient way to manage their patterns.

MCPat is further described here.

ASDF-install package (obsolete) http://www.sfmishras.com/smishra/mcpat/download/mcpat.tar.gz

Okay, I'm interested, but what can it do? There is not much in terms of documentation. Can someone provide some uses/examples where this will do something better/easier than say, fare-matcher? Or even point me to a project that uses it and I can ponder their source code. --Zach